There are two reasons why not to use a round connector for USB or similar roles. First is power, a round connector makes it a lot harder to do hotplug safely, where the ground connects first and power can not inadvertently be shorted to other pins by partial or offset insertion. Live power also shouldn't be connected to exposed surfaces.

The second reason is high-speed signaling is very picky about electrical connections and positioning. Note how ethernet doesn't just connect the four pairs in 12345678 order, but mixes them up. This is to keep the signal lines appropriately separated. A connector that works over its width is a lot easier to do this with than one that has to be inserted inline.

A barrel plug like is usually used for power doesn't cut it for multiple signals and a stereo/headphone style jack has exposed conductors. Pretty much anything else isn't able to be inserted rotated, which would be the whole benefit of a round connector. Otherwise you end up with DIN-style connectors (think PS/2, ADB, and S-Video) which are just as bad as USB in terms of plugging in blind.Reply

Not enough space on a thin device for anything but a flat connector. Round is also only simple if you can have concentric contacts like a headphone jack. Otherwise orienting a circular connector is far worse than a flat one. A reversible flat connector does seem best.Reply

I recently had to upgrade my nexus7 tablet, as the 2012 version uses the tiny usb port to charge, and it's fragile. Our kids kept tripping over it. Something bent inside and charging became very difficult. So ... I hope the new connector port builds some reliability into it to take abuse and keep working.Reply

Well of course there IS a solution to this --- make the thing magnetic like Apple did...

I'm not sure why Lighting is not magnetic like MagSafe. I keep hoping it's because Apple didn't have time to iron the bugs out, and it's coming; but maybe it's basic physics --- maybe there simply isn't enough space to stick a magnet large enough to do the job in a phone, and prevent it from interfering with the speaker?Reply

Nonsense...the reason is because Apple is cheap and desperately clings onto insane profit margins. The Sony Xperia Z1 smartphone has a magnetic charger port just like MagSafe. They even sell a cool magnetic charger dock so you just plop the phone in and it charges. But also a magnetic charging cable with USB on the other end. It's on the side of the device. But it also includes a MicroUSB slot for data transfer.Reply

I get that USB3.0 is rated at a theoretical 5Gbps vs sata 6Gbps but that doesn't really mean much when it comes to how the specs are designed to work compared to each other when transferring filesReply

The issue is not "theoretical" speed.The issue is that the speed you are talking about is a PHY speed --- the speed at which individual bits are clocked on the wire.(a) Nothing in the spec says this speed has to be sustained. Early HW is allowed to (did with USB 2, and likely does with USB3) have buffers that are large enough to send or receive a single packet at this speed, but without the overall throughput that allows this to be sustained for multiple successive packets,

(b) The PHY rate is not the MAC rate. USB is a bus with possible multiple devices on it. There is some MAC protocol for deciding who gets control of the bus when. This protocol appears to be pretty inefficient (at least in the case of USB2) dropping about 25% of performance on the floor, and I would guess the USB3 MAC protocol is pretty much the same.

(c) Most USB drives use the older USB MSC protocol for communicating with the drive, not the newer UAS protocol which is supposed to allow for higher performance (by allowing things like NCQ commands to travel over the wire). This doesn't necessarily speed up bulk transfers, but if UAS allows for larger packets than does MSC (I don't know if this is true) it would allow for higher speed.Reply

I can think of a bunch. SuperSpeed USB and eSATA 6Gb/s have nominal data rates of 5 Gbit/s and 6 Gbit/s respectively, and both use 8b/10b encoding. Theoretically this gives eSATA 6Gb/s a 100 MB/s advantage, however, if the connected drive is the limiting factor because it can't exceed 440 MB/s (as is often the case) this advantage is irrelevant. If both ports are provided by discrete controllers that only have PCIe 2.0 x1 connections to the host (another common scenario), then eSATA's advantage once again disappears. In order to support 6Gb/s operation, the drive, enclosure (if you're using one) and port you're connecting to must all support 6Gb/s, otherwise the pendulum swings in favor of USB 3.0.

Plugging a cheap USB 3.0 external that supports UASP into a SuperSpeed port provided by an Intel or AMD PCH/FCH is generally going to yield better performance than connecting a drive via eSATA to a port provided by a discrete controller, unless that controller has more than a PCIe 2.0 x1 back end, which would be a rarity on most motherboards. If the eSATA 6Gb/s port is provided by the chipset, it can put up a fight. However, UASP allows better use of the full-duplex channels provided by USB 3.0, and can actually reduce latency and protocol overhead compared to the still stuck on simplex SATA.Reply

Despite what the theoretical numbers say, the actual behavior is quite different and why I'm currently unhappy with USB3 for file transfers. The only case where I have ever personally seen USB3 beat eSATA in writes was in large file transfers from an SSD. If every other case, even eSATA 3Gb/s was much faster. Particularly with small files where USB3 got slower until it leveled off at about 20 MB/s whereas eSATA was 60MB/s plus. I tried this with and without turbo mode in the BIOS.Until I can see fast USB performance, I'll hang onto my external eSATA docks.Reply

I'm guessing you're either using a port supplied by a discrete USB 3.0 controller, not experiencing any UASP love, or both.

Make sure whatever you are using for a SATA to USB 3.0 bridge supports UASP, plug directly into a USB 3.0 port provided by an Intel 7 or 8 series PCH or AMD A70M, A75 or A85X FCH with no intervening hubs and whatnot, and that you're running Windows 8/8.1.

A decent SSD connected via USB 3.0 to an Intel Z77 system can push 200 MB/s of small random reads/writes, which is comparable to any discrete eSATA 6Gb/s solution even at high queue depths.

Of course eSATA to SATA is still the only way to go for issuing an ATA secure erase command or updating firmware on most drives.Reply

I don't think that the engineers who developed USB in the mid-90s, mainly for small computer periphals like mice, keyboards, or plug-it-and-forget-it things like printers, had ultra-thin smartphones in mind when they designed the connector ;)And I prefer different mechanical connectors with a single universal interface rather than different interfaces. And backwards compatibility is quite handful.

And it is the same for HDMI. It was designed as a replacement for SCART/S-Video + audio connections. For TVs and stuff. It was not designed to be used with handheld device outputting full HD content, being constantly plugged on and off.

Of course, a single universal small connector is more practical. But I can understand that when people thought this connectors 10 to 20 years ago, they did not imagine what we would do with them now ;)Reply